480 million patients around the globe suffer from neurological disorders which are the fastest-growing disease worldwide. Many neurological and psychiatric conditions are the result of abnormal neurotransmitter concentrations in the brain. Our ultimate goal is to develop a nano-neural-prosthetic device that can maintain therapeutic levels of chemical concentrations in the brain in real time exploiting closed-loop delivery method. The nanosystem consists of neural probes fitted with novel sensors and embedded negative feedback circuits that will control the flow of neurotrophic-factor agents in microfluidic channels. The negative consequences of systemic drug-delivery and aberrant neurotransmitter concentrations will be eliminated by personalizing neurotherapy and delivering neurotrophic-factor at the exact required location. We developed a low power neurotransmitter bio-sensor which can be applied in an implantable closed-loop CMOS neurotrophic factor delivery nanosystem which by protecting the healthy neurons and restoring damaged ones can maintain therapeutic levels of chemical concentrations in the brain. it consist of novel biosensor that can sense micromolar concentration of neurotransmitters and embedded negative feedback circuits that control the flow of pharmacological agents in micro fluidic channels. Additionally MEMS (Micro Electro Mechanical System) pumps connected to the probes to inject micromolar concentration of neurotrophic factors into the brain.